Two minor reports concerning GHC

[Graham Klyne]

I've noticed a couple of very minor issues with GHC[i]:

(1) unhelpful error message from GHCi:

[[
Compiling ParsecPrim       ( F:\Haskell\Lib/ParsecPrim.hs, interpreted )
WARNING: ignoring polymorphic case in interpreted mode.
    Possibly due to strict polymorphic/functional constructor args.
    Your program may leak space unexpectedly.
]]
I don't understand what this is trying to say, and the lack of a source 
code line number doesn't give me any chance to study the code for 
clues.  This warning is GHCi only.

(2) Strange behaviour of GHCs Time.diffClockTimes function:

This code fragment:
[[
runTest t =
     do  { st <- Time.getClockTime
         ; putStr $ "Test started:  "++show st++"\n"
         ; runTestTT t
         ; ft <- Time.getClockTime
         ; putStr $ "Test finished: "++show ft++"\n"
         ; let et = Time.diffClockTimes ft st
         ; putStr $ "Test duration: "++show et++"\n"
         }
]]

yields this output:
[[
Test duration: TimeDiff {tdYear = 0, tdMonth = 0, tdDay = 0, tdHour = 0, 
tdMin = 0, tdSec = 9, tdPicosec = -437000000000}
]]

In particular, tdSec and tdPicosec have different signs.  I don't see what 
reasonable implementation would yield such a result.  I've observed this 
with programs running interactively under GHCi, and also stand-alone 
executables.

These tests using GHC 5.04.3, on Windows 2000.

#g
--

BTW, I found the GHC profiler to be very useful, and easy to use.  I'm 
impressed!



-------------------
Graham Klyne
<GK@NineByNine.org>
PGP: 0FAA 69FF C083 000B A2E9  A131 01B9 1C7A DBCA CB5E